Journal of Ornamental Plants
Volume:14 Issue: 2, Spring 2024

Drought is the most important environmental stress, which is usually defined as an external factor that has adverse effects in plants. The endangered yew species is very important for human societies for medicinal and ornamental reasons. The roots and leaves of this plant produce biochemical compounds such as flavonoids, alkaloids and tannins that act as anti-inflammatory, anti-cancer, anti-bacterial and anti-viral. The present research investigated the effect of different levels of drought stress (100, 75, 50 and 25% of field capacity) on the growth and biochemical characteristics of the yew plant in a greenhouse environment in three replications in the form of a completely randomized design. In this research, which used 3-year-old seedlings, the fresh-to-dry weight ratio of shoots and roots, chlorophyll a and b and the ratio of these two, the relative content of leaf water, the activity of superoxide dismutase and catalase enzymes, and the percentage and yield of essential oil were evaluated. The results showed that the growth traits and photosynthetic pigments and the relative water content of the leaves decreased with the increase in the severity of drought stress. Of course, the activity of catalase and superoxide dismutase enzymes increased with the intensity of drought stress. The highest percentage of essential oil was obtained in semi-severe drought stress conditions (50% F.C). With the increase of drought stress up to 25% F.C, the percentage of essential oil decreased. Most of the growth and physiology parameters of yew plant at 75% FC compared to 100% FC were not significantly different, so it seems that this plant shows good tolerance in the condition of 75% FC and has an acceptable yield. Therefore, it is recommended to cultivate this valuable plant in favorable environmental conditions with sufficient water and/or with only in mild stress conditions.

Alstroemeria is one of the most important cut flower crops globally, known for its diversity in color, various cultivars, and overall beauty, contributing to its success in the global market. The use of different preservative solutions at various stages of cut flower supply to the market plays a critical role in preventing ethylene production and maintaining the water balance and energy supply required for the plant after being separated from the mother plant. Therefore, this investigation effect of 1-methylcyclopropene (1-MCP) and methyl jasmonate (MeJA) on the post-harvest life of alstroemeria (cv. Calgary) cut flowers was conducted in the Department of Horticultural Science and Landscape Architecture, Faculty of Agriculture, Ferdowsi University of Mashhad. The experiment was done in a factorial design (3 × 3) with five repetitions for each treatment. The results of the main effect of methyl jasmonate (MeJA) application showed that the highest water uptake, relative fresh weight, vase life, chlorophyll a and b, anthocyanin, catalase, peroxidase, and superoxide dismutase were observed at a concentration of 0.2 µL/L of MeJA. The main effect of 1-MCP application showed that the highest water uptake, relative fresh weight, vase life, chlorophyll a and b, anthocyanin, catalase, peroxidase, and superoxide dismutase were observed at a concentration of 1 µL/L of 1-MCP. The results of the interaction effect between MeJA and 1-MCP application showed that the highest water uptake, relative fresh weight, vase life, chlorophyll a and b, anthocyanin, and antioxidant enzymes were observed in the treatment with 4% sucrose+300 mg l-1 8-HQS+1 µL/L 1-MCP + 0.2 µL/L MeJA.

Root and collar rot of Thuja caused by Fusarium oxysporum is one of the important diseases in Thuja cultivation. In this research, the effect of eight bacterial strains of Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus subtilis, Bacillus velezensis, Pseudomonas flurescens, Pseudomonas koreensi and Pseudomonas putida in controlling this disease was investigated in the laboratory. Among them, based on the dual culture test and observation of the inhibition zone, B. velezensis and B. subtilis had the highest inhibition with 9.33% and 5.6%, respectively. In the study of the effectiveness of non-simultaneous antifungal volatile compounds, P. flurescens had the highest inhibition with 58.33%. The simultaneous volatile compounds of P. koreensi, P. flurescens, B. pumilus, and B. megaterium completely controlled the disease agent. In the study of the effect of filtered extracellular liquid metabolites on the growth of the pathogen colony, it was observed that with the increase in the concentration of the metabolites, the inhibition percentage of the growth of the pathogen colony by all bacterial strains increases. The best strains against F. oxysporum were B. velezensis, B. subtilis, and B. pumilus strains, which in 25% concentration were 50, 72.27 and 86.67%, respectively, and in 15% concentration B. pumilus strain was 66. 75% and B. velezensis strain with 46.66% inhibition, and at 5% concentration, B. pumilus strain with 44% inhibited the growth of the fungal colony. In the protease production test, all isolates were able to produce protease. Only P. fluorescent strain was able to produce a siderophore. In the microscopic studies, all the investigated strains caused morphological changes, fusion of different parts of the filaments, and destruction.

The production and maintenance of ornamental plants are closely related to the high consumption of fresh water. Today, due to the limited water resources, we have to water plants with salt water sources. To evaluate the effects of foliar application of nano TiO2, CeO2, and quantum dot-graphene oxide (zero and 1.5 mg/L) and NaCl salinity stress (0, 75, 150 mM) on Gazania splendens L.; a factorial experiment was conducted based on completely randomized design. The results revealed that plant dry weight, flower number, proline and flavonoids content, antioxidant enzymes activity, MDA, H2O2, Na, N, and P content were influenced by the interaction effects of experimental treatments. The highest leaf dry weight, flower number, and N content were recorded at no-salinity × quantum dot-graphene oxide. The highest data for Na content, ion leakage (56.6%), H2O2 (246 nmol/mg FW), malondialdehyde (37 nmol/mg FW), and proline (1.1nmol/mg FW) content were recorded at NaCl150 mM × no-foliar spray. 150 mM salinity stress × quantum dot-graphene oxide increased catalase activity (8.9 µmol/g FW) in the plant. Superoxide dismutase and ascorbate peroxidase activity were influenced by NaCl150 mM × quantum dot-graphene oxide and TiO2 foliar spray. Chlorophyll index, total phenolics, and K/Na ratio were responded to the simple effects of salinity and foliar application. The top ratio of K/Na and chlorophyll index was recorded at quantum dot-graphene oxide foliar spray. 75 and 150 mM salinity improved phenolics content in plants. Foliar spray with all nanoparticles increased phenolics content. The overall results showed that salinity had adverse effects on the growth and physiological characteristics of Gazania splendens. Foliar treatments under 150 mM salinity stress; promisingly influenced the antioxidant enzymes activity and root dry weight of plants. All in all, Gazania splendens can tolerate up to 75 mM NaCl salinity stress without a remarkable decline in growth and physiological attributes.

Ornamental plants are one of the cheapest and most natural elements for air purification and pollution reduction. The ability of this type of plant species to absorb pollutants and purify the air is undeniable. Today, due to industrialization and technological progress, air and environmental pollution has become an important concern in developing countries. The purpose of this research is the effect of ornamental plant species in reducing pollution and purifying the air of sports venues. Pollutants that affect the cleanliness of sports places include: Benzene, Formaldehyde, Carbon Monoxide, Trichloroethylene, Ammonia, Fume and Xylene. Eight plant species include: English ivy (Hedera helix), Aloe vera, devil's ivy (Epipremnum aureum), dwarf date palm (Phoenix roebelenii), spider plant (Chlorphytum comosum), variegated snake plant (Sansevieria trifasciata 'Laurentii'), boston fern (Nephrolepis exaltata 'Bostoniensis') and bamboo palm (Chamaedorea seifrizii). In order to purify the air and reduce pollution, pollutants were investigated for air purification and reduction of pollutants in this research. According to the results of this research (P < 0.05), the necessary information to predict the correlation of air purification with different plant species statistically showed that, based on the model, eight studied plant species have a natural correlation with air purification and Sansevieria trifasciata has the greatest effect in reducing pollution and purifying the air of sports venues (Beta = 0.348, Value = 0.966). The results showed that in any part of the world, the studied plant species are among the most effective species in air purification, so they are suitable for streets, parks and sports places. It is suggested that by using the results of this research, the relevant officials and stakeholders should pay more attention and use the mentioned plants to improve the air quality of the city and sports facilities.

The present study aims to investigate the effect of different levels of vermicompost on the growth and yield of the essential oil of marigold plant under seed priming with Azospirillum and humic acid under different levels of vermicompost on the growth and yield of marigold essential oil, factorial based on a randomized complete block design in the research farm of Islamic Azad University, Astara branch was done. The test treatments included seed priming including Azospirillum brazilense bacteria, humic acid, Azospirillum + humic acid and control and different levels of vermicompost (0, 5 and 10 t ha-1). The results showed that some traits such as chlorophyll a, anthocyanin, essential oil yield and biological yield were affected by vermicompost interaction and seed priming. But plant height, number of seeds and flowers, flower weight, seed weight, essential oil amount and total chlorophyll were affected by the main effect of vermicompost, but seed priming was not significant on some of these traits. The highest amounts of chlorophyll a and total, biological yield, essential oil yield and dry weight of flowers were obtained from humic acid + Azospirillum treatment under the application of 10 t vermicompost ha-1.